CLEARWATER, Fla. (AP) A dazzling, 16-strikeout performance was the best and worst thing that happened to Vince Velasquez last season.

The hard-throwing righty quickly showed his electric stuff in his second start with the Philadelphia Phillies, tossing a three-hitter with no walks and 16 Ks against San Diego last April.

But Velasquez spent the rest of the season trying to do it again.

"When you have a performance like that, you want to repeat it as much as you can, you want do it every outing," Velasquez said. "It was one of the best experiences in my life. It was remarkable. It was a big eye opener.

"After I had that experience, I thought it was going to be easy, but that's what happens when you take things for granted and you try to repeat it. Things happen and you have to move on."

Velasquez only pitched more than six innings twice again and fanned 10 two more times. He was 8-2 at the All-Star break but didn't win another game, finishing 8-6 with a 4.12 ERA in 24 starts. Velasquez had 152 strikeouts in 131 innings.

"Even though I had a lot of success, I had a lot of failure," Velasquez said. "There's a lot of learning from that. There's certain aspects, there's analytics and more factors than just throwing a baseball."

The numbers said Velasquez needs to work on improving his curveball. He relied mostly on his fastball, which averaged 94 mph. Velasquez only threw his curve 13.6 percent of his pitches and batters hit .297 against him when he used it.

"The curveball could be a huge factor if I could locate it and use it whenever I want," Velasquez said. "If I can get strikes with my curveball, I won't have to worry about throwing a lot of extra pitches and I'll be able to get guys out earlier."

The Phillies acquired Velasquez along with four other players, including 2013 No. 1 overall draft pick Mark Appel, in a trade that sent young closer Ken Giles to Houston. The 24-year-old Velasquez won a competition for the fifth starter spot last spring and became a key part of a promising, young rotation.

If he stays healthy, learns to mix his pitches and can pitch deeper into games, Velasquez could be a top-of-the-rotation pitcher.

"I realize my potential and that's why I'm working hard," Velasquez said. "I would love to be a No. 1 starter. I would love to be an opening day starter. But there are a lot of factors that play into it. I have a lot of work to do to show these people what I can be."

Velasquez got caught up trying to prove he wasn't a fluke or a one-hit wonder last year. He has the physical skills and the desire to succeed.

"I think he has the capacity, mentally, to make adjustments and learn from his mistakes," manager Pete Mackanin said. "Over time, I think he has a chance to be an ace."

Velasquez is an excitable and emotional guy and sometimes that works against him. He wasn't happy with an umpire's strike zone in an outing against Toronto this spring and it was clear by his reaction on the mound.

"We want true competitors," Mackanin said. "Although you need to compose yourself, I can understand a guy getting upset as long as you don't show the umpire up."

Velasquez is determined to have an excellent season from start to finish.

"There's more ahead," he said. "You always have to be optimistic and strive to do more because there's always room for improvement. You can't take things for granted."